Resinous materials of N-(isobutoxymethyl)acrylamide, styrene, butadiene and an aldehyde are disclosed in U.S. Pat. Nos. 3,118,952 and 3,037,963 and can be utilized to form coating films having good flexibility, recoat adhesion as well as resistance to marring, staining, heat, detergents and corrosion. U.S. Pat. No. 3,037,963 discloses the method for making such materials in the presence of an organic solvent such as alcohol. By conducting a similar polymerization and blending the resinous material with a polymer of an aliphatic unsaturated alcohol or another resin, such as epoxide or vinyl, the composition disclosed in U.S. Pat. No. 3,118,852 is obtained with the advantage of having a lower curing temperature. Recognizing that these compositions have utility as finishes for appliances, lowering their curing temperature facilitates optimum coating. While the resistance of such coatings and their relative ease of application has significance, neither bears any relation on improving the green strength or elongation of synthetic rubber such as SBR.
U.S. Pat. No. 3,247,139 discloses an aqueous process for the preparation of aldehyde-modified carboxylic acid amide polymers in those instances where an organic solvent system is not desirable but a water base system is. Although the components of the polymers include derivatives of acrylamides and styrene and butadiene, other components are also incorporated and again there is neither a recognition nor a suggestion that an SBR having a small amount of an N-(alkoxymethyl)acrylamide would exhibit improved green strength properties.
Thus, preparation of a polymer comprising an N-(alkoxymethyl)acrylamide, a diene and a monomer containing a vinyl group as a means to improve physical properties of synthetic rubber comprising the latter two monomers such as SBR has not been disclosed in the patents of which we are aware.